User's Guide

For the purposes of this copyright and license, "Contributing Authors" is defined as the following set of
individuals:
Andreas Dilger
Dave Martindale
Guy Eric Schalnat
Paul Schmidt
Tim Wegner
The PNG Reference Library is supplied "AS IS". The Contributing Authors and Group 42, Inc. disclaim all
warranties, expressed or implied, including, without limitation, the warranties of merchantability and of
fitness for any purpose. The Contributing Authors and Group 42, Inc. assume no liability for direct,
indirect, incidental, special, exemplary, or consequential damages, which may result from the use of the
PNG Reference Library, even if advised of the possibility of such damage.
Permission is hereby granted to use, copy, modify, and distribute this source code, or portions hereof, for
any purpose, without fee, subject to the following restrictions:
1. The origin of this source code must not be misrepresented.
2. Altered versions must be plainly marked as such and must not be misrepresented as being the
original source.
3. This Copyright notice may not be removed or altered from any source or altered source distribution.
The Contributing Authors and Group 42, Inc. specifically permit, without fee, and encourage the use of
this source code as a component to supporting the PNG file format in commercial products. If you use
this source code in a product, acknowledgment is not required but would be appreciated.
A "png_get_copyright" function is available, for convenient use in "about" boxes and the like:
printf("%s",png_get_copyright(NULL));
Also, the PNG logo (in PNG format, of course) is supplied in the files "pngbar.png" and "pngbar.jpg
(88x31) and "pngnow.png" (98x31).
Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a certification mark of the
Open Source Initiative.
Glenn Randers-Pehrson
[e-mail]
September 12, 2004
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